1. Field of the Invention
The present invention relates to an image forming apparatus and an image forming method, and more particularly to technology for controlling the level of gloss of an image formed on a recording medium.
2. Description of the Related Art
Japanese Patent Application Publication No. 2006-239685 discloses a method of varnishing an image by an inkjet method, wherein droplets of varnish are deposited in a screen pattern in order to adjust and control the level of gloss. According to this method, an ultraviolet (UV) curable varnish having high fluidity is used if a highly glossy surface is to be formed, while another UV-curable varnish having low fluidity is used if a matte surface of low gloss is to be formed. In other words, it is necessary to switch between the use of different UV-curable varnishes having different wetting properties (fluidities), in order to obtain images having different gloss levels. Therefore, this method is not suitable for printing small numbers of prints, since there is an increase in the labor input, time and costs, and the like, required in switching the UV-curable varnishes, and hence there is a problem in that small numbers of prints cannot be made efficiently and quickly.
Japanese Patent Application Publication No. 2006-015691 discloses a method in which the surface of a medium on which an image (a picture and/or text characters) has been printed by means of an inkjet printer using UV-curable ink is coated with a clear coating layer made of a transparent or semi-transparent clear ink having as a main component a resin having a reflectivity that is the same or substantially the same within an error range of ±0.5 with respect to the resin forming the main component of the ink contained in a plurality of UV-curable ink dots composing the image. According to this method, the light reflected by the surface of the ink dots composing the image printed on the surface of the recording medium is not reflected randomly at the interfaces between the ink dots and the clear coating layer, but rather is reflected in substantially parallel directions upwards from the surface of the recording medium, and hence the gloss of the surface of the image coated with the clear coating surface is raised and the quality of the image is improved. In this method, however, no consideration is given to changing the gloss of the image and it is not possible to achieve images having different gloss levels.